Apparatus for drying substances



Sept l, 1925.

C;` REES ET AL APPARATUS FOR DRYING SUBSTANCES Fi d Dec. 9. 1920 4 Sheets-Sheet 1 #HMI sept. 1, 1925, 1,551,846

C. REES ET AL APPARATUS FOR DRYING SUBSTANCES Filed Dec. 9,'1920 4 sheets-sheet Q Q l' J K I N N8 Q l L, N i

d llO) W ATTORNE Ys c. REEs ET AL 4APPARATUS FOR DRYING SUBSTANGES Filed Dec. 9, 1920 4 sheets-$11561' s IN VEN TOR 5 'WITNESS CZ fu/0E Fees Mja/1Mo and Cfr/1m fs /F/f/NE L-Vi/ATTORNEYS MGM/w swf. 1, 192,5.

C. REES ET AL APPARATUS FOR DRYING SUBSTANCES Filed Dec. 9, 1920 INVENTORS WITNSS 01h/M4 L uw .c H @A m v E M uw O n H T. L C T MY. B

l Patented sept. *1, 1925.

N UNITED vsi'aias PATENT .o1-*Fica '..cLAU'nE sans, or'sAN rnANcIsco, AND cHAnLEs r. EINE, or OAKLAND, cALrroRNIA.

APPARATUS FOB. DBYIN SUBSTANCES.

Application mea December a, 1920.- serial No. 429,2.

lTo all whom it may concern: x

Be it known that we, CLAUDE Rnnsand CHARLES F. HINE, citizens of the United States, and residents, respectively, of the city and county of San Francisco, and of Oakland, county of Alameda, both in the `State of California, have inventedocertain new and useful Apparatus for Drying vSubstances, of which the following'v is a specilication.

This invention relates to a novel drying system involving the apparatus by which various kinds of substances, and particularly fruits, may be efficiently and rapidly dried to a predetermined degree.

It 1s very desirable in the drying of certain materials and, particularly, in the drying of fruits as, for instance, prunes, that warm or hot air be passed over and between the substance. and yet preserve such a degree of moisture or humidity in the air as will prevent the too rapid drying of the eX- terior-and outermost portion of -the fruit.

To that end it is an object of the present invention to providea system of great capacity and yet of high economy for the drying of fruit in the desired manner and,

particularly, it is an object to provide an apparatusin which the substance or fruit being dried may be subjected to circulated air in which the desireddeoree of moisture or humidity and the desired temperature to secure an economical operation in cost of fuel and to accelerate the process of drying.

It is an object of the invention to provide an apparatus which,while of substantlal and simple construction, enables predetermining 'the course of flow of heated air through the apparatus and itis an object to provide for .40 the control of the circulation of the air and for the substantially constant discharge of a portion of a used, moist air and-the admission of fresh air to replace the exhausted a1r.

It is also an object to provide for the heating of the air before it is discharged into the heating or drying chamber and to provide for the initial heatingu of the air before it passes to the heating means direct and also to 5 0 provide means for returning a portion of the used, moist air to the heating means so that' it will be 4reheated, 'thus providing for the substantially constant circulation and re-circulation ofa portion of the air that tal vsection of has absorbed moisture from, the substances being dried, at the same time exhausting a lportion of the moist air and supplying fresh air in replacement thereof.

The invention possesses other objects and i features of advantage, some of which, with the foregoing, will be made manifest in the following description of the preferred forml of the invention which is illustrated in the drawings accompanying and forming part of the specification. It is to ,be understood that it is not intended to limit the invention to the embodiment shown by the said drawings and description as variations may be adapted within the scope of the invention as set forth in the claims.

Referring to said drawings: Fig. 1 is a a preferred form of the apparatus. n

Fig. 2 is a transverse vertical section through the apparatus substantially'on line 2-2 of Fig. 1.

Fig. 3 is a longitudinal vertical sectional view substantiallyon line 3 3 of Fig. 1.

Fig. 4 is a vertical longitudinal sectional viewsubstantially on line-4 4 of Fig. 1.

Fig. 5 is a horizontal sectional view substantlally on line 5 5 of Fig. 2.

In the preferred embodiment of the in-l vention the system comprehends the utilization of a drying-house of suitablematerial and dimensions, the latter being determined by the desired operating capacity. The drying house is preferably of elongated form to facilitate the arrangement therein of a row of tiers, ly separated or spaced layers of the material to be dried and the layers are preferabl arranged in trays of such construction arrangement that horizontal passageways are formed lbetween the layers to secure the effective traverse of a' drying medium such as heated air. To secure efficient, economical and rapiddrying of the desired product, the drying house is preferably divided plan View partially in horizon-'.

each tier comprising vertical- Y into a longitudinal heat chamber extending lie longitudinally; lthe `contlguous vertical sides of the radiators beling disposed adjacent a partition or wall structure forming vertical openings through which air may pass readily from and toward the radiators as determined bythe operation of suitable mechanical circulating devices arranged in the drying house.

To secure the desired course of' Circulation of the heated air through the wall or partition contiguous to the radiators there is arranged, at a suitable'height above the licor of the drying house, a horizontal partition or ceiling-like structurebeneath which p the tiers of layers of substance to be dried can be passed so that the toplayers of the tiers are in close roximityto the lower surfaces of the ceiling structure to prevent too free and rapid iow of the heated air immediately beneath the ceiling surface.

' The drying house is provided with a longitudinal passageway along its opposite side withrespect to the heat chamber and which is in free transverse communication with the circulating space formed above the ceiling structure and which space is also in longitudinal heatchamber and the longituand advantageous. Also, .an ,important fea-A in replacement of ,the exhaus dinal pasageway at the opposite side of the house, therefore also permitting the ready circulation of the heated air in either direction through the top s aces abovethe ceiling by meansv of suitab e mechanical devicesl which may be controlled so as totreverse the direction of flow of the' air at suitable intervals to secure the equable drying e'ect upon the substance.

An important feature of the present` inventionv resides in the provision for not only circulating heated air to and fro upon the substance to be dried but also in re-using a selected portion of the -'heated air that has' been passed over the substance :and that has absorbed moisture therefrom, thus enabling the application of heat to one end of the row of tiers throu h a medium that possesses such a desirale degree of moisture or humidity as is found extremely practicable ture is to provide forthe substantially continuous discharge of a selected portion of the airafter it has been circulated over the substance and, further, provides also for the admision of a suitable quantit Iof fresh air air. Again, it is desirable to economize in the cost 'of heating the air by utilizing, as above stated, a portion ofthe previously heated and circulated air and directing this selected portion to `means byV which it is re-heated.'

Flurther, it is desirable'topreheat the fresh air passing into the apparatus before it is with pulley wheels or otherdrivin It is further a feature of the invention to provide for the variable control of the course of flow of the heated air through thedrying house somewhat independently of themechanical air circulating means and it is also a feature vto provide for the ready observation of and access to various tiers of substance while being dried, atthe same time without materially disturbing the desired conditions existing in the drying house during the operation of the system.

The system as here .disclosed involves a drying house 2 of any suitable material and dimensions andmay be of rectangular cross section or otherwise as desired and, for convenient introduction and discharge of the substance to be dried within the drying house, a trackway 3 is extended longitu-` IThe ceiling 7 is of less horizontal width than the width of the drying house 2 and there is, therefore, formed along one side edgeof the ceiljn'gla free opening 9 while at thefopposite edge ere is a similar free opening 10 and at suitable longitudinally Vspaced distances there are transverse vertical partitions 11 for -dening spaces above the ceiling 7 in "which arearran ed suitable mechanical means, as circulating fans 12', secured on' shafts 13 that are shown as extending through the side wall 14 and are provided means 15 which receive respective pulley extended in a series longitudinally/ of the wall 14. One of the shafts 13 is provided with a tight intermediate pulley 17 flanked by loose. ulleys 18 and 19 and from this set of eys extends an open and laterally shiftab e belt 20 and a cross belt 21 which turn about a driving pulley 22 of the necessary width to accommodate the belts 20 and 21 in their several positions so that the driving pulley may be utilized when operating in one direction through means of the belts 20 and 21 to drive the tight pulley 17 in either direction at intervals during the operation of the drying system and, therefore, securingthe rotation of the several fans o r propellers 12 on shafts 13 in either directionin their respective sub-spaces above the ceiling 7 and serving to control the direction' of circulation of air through the space :and sub-spaces above the ceiling for a purpose to be described. When desired, the fan on the shaft 13 may be omitted. i

elts 16 f The transverse partitions 11 extend from the ceiling 7 to the side wall 14 and beneath the lower edgeof each of the kpartitions at the opening 10 there is disposed a preferably movable partition or door 23 hinged `or otherwise pivotally connected toY the wall 14 and having its swinging edge disposed to rest vclose to an upright or post 24 of which there is a series extending through the drying house in such position as to clear the tiers of material to be dried that are run into the house on the trucks 4. For the purpose of preventing 'longitudinal leakage of the air in the house past the ends of the tiers, a small vertically hinged shutter 25 may be attached to one side of each of the posts 24; the shutter 25 being hinged so that it is movable toward the contiguous corner of a tier of trays or racks 6, as plainly shown. in Fig. 1, to direct the air coming through the opening 10 at the edge of the ceiling 7 laterally toward the tiers. The rate of longitudinal progression o-f the air may, therefore, be controlled by a suitable angular disposition of the doors 23. This construction, therefore, provides a longitudinal passageway 26 between the wall 14 and the adjacent side of the row of tiers 5 disposed in the drying house through which passageway operatives may have ready passage fr'om one end of the drying house to the other for the convenient inspectionof the substance being dried and for the determination of the draft and temperature conditions existing within the house. The tiers 5 being coordinate with the transverse par titions 11 from sub-divisions of the longitudinal passageway 26 and prevent the uninterrupted longitudinal flow of air through the house.y

To secure the desired and economical heating of the air in the drying house and to secure a substantially constant discharge of a portion of the air and its replacement by fresh air, suitable air heating and supplying means are provided and also suitable means for directing aselected portion of the moisture laden air coming from the substance being dried to suitable portions of the heat-ing means. A preferred form of means for admitting air into the drying house consists of a tunnel-like structure 30 that is preferably constructed of masonry or concrete and which is shown as disposed in the Hoor ofthe drying house and spaced inwardly from the longitudinal side wall 31* thereof. 'The tunnel v`is shown as being sunken somewhat below the Hoor and extending upwardly a suitable distance there-` from, onelongitudinal .side ofthe tunnel 30 "paralleling' the rraekway 3; At theopl positcsides-"fthetritcltway therefare ro? vided a series 'fadj'clsiires-'or Is fut- Y ters 32 that maybeffp' ted'at'their lower. egesireaea .panel spart: 44 adiafae swung toward the bottom trays of the tiers and, therefore, preventing the passage of air transversely beneath the bottom of the tiers.

The house 2 may be of any length, as stated, and as shown has capacity for containing six trucks of tiers which extend substantially from end to end of the house, one end being provided with an ingress door structure 34 while the opposite end is provided with an exit door structure 35. The air tunnel 30 extends along the floor of the drying house from a position at one end adjacent the outlet door 35 forwardly to a suitable point at which there may be provided an L-shaft or branch 30 extendin horizontally and provided with an int 'e mouth 30a through which fresh air may pass into the branch 30 and the tunnel 30 proper. The tunnel 30 is shown as about equal in length to the length of a series of four tiers of the trays on trucks 4 and arranged upon the top of the tunnel in a longitudinal row thereon and in spaced relation to register medially with the tiers 5 are suitable types of radiator structures comprising each, for instance, a bottom manifold 37 and a top manifold or header 38 between which extend vertical rows of heat flues or tubes 39 through which heated air may be circulated in a predetermined course.

The tubes of the radiator stand in suitable spaced relation from the wall 3l in rows that are parallel to the wall and to the adjacent sides of the tiers of trays so that there is formed along the inside surface of the wall 31 a heat chamber 40. For the 4effectual cont-rol of the flow of air to and from the chamber 40 past the radiating tubes 39 of the radiators and toward and from the horizontal spaces between the layers of material in the trays in the tiers 5 suitable deflecting Walls of partitions 41 are arranged vertically and with their planes oblique to the length of the central dryinor room in which the tiers are arrange contiguous partitions 41 converging inwardly and meeting at 42' so that heated air passing fromthe heat chamber 40 -through the radiators "may freely spread when vpassing the diagonal partitions 41 and, conversely, the heated air passing from the tiers toward the radiators is converged in streams directed intimately against the radiator tubes. To prevent free longitudinalmovement'of heated air along the longitudinal heat chamber 40`during the operation of the apparatus, suitable transversely extending doors 43 lare the' sidewall 31'ito a 'stationary support and the angle 42;; of the obliquefdaecrofsa y y ,y melting i i fires-'realy @191efn @esima-refiere,

To secure the maximum eiiiciency of heating apparatus for the economical heating of fresh and re-circulated air in the apparatus adjacent pairs of the radiators, including` the lower manifolds 37 the upper manifolds 38 and the connecting tubes 39, are servedv by common furnaces 45 of any suitable type which are shown as extending laterali from drying house 2 through the side wa l 31, each furnace discharging its hot gases and products of combustion into the respective horizontal drum 46-47, Fig. 4, which drums are disposed in the tunnel 30. The drum 46 serves the pair of radiators adjacent the discharge end and is connected to these radiators throughI upwardly extending tubes 48 leading into the bottom of the adjacent bottom manifold, as 37, from which the heated gases pass into the connecting tubes 39 while the longitudinally extending heat drum 47 is similarly connected to the forward pair of radiators through connecting tubes 49 leading into the bottom manifolds 37 of the respective radiators. The several connecting tubes 4849 may be and preferably are provided with regulating dampers 50. Fresh air passing into the mouth 30a ofthe tunnel 30 flows longitudinally through the tunnel 30 which is provided at a suitable location adjacent its rear end with a small discharge aperture 51 in the side of the tunnel adjacent the wall 31, and further beyond is 'provided with a larger discharge opening 52 through which the fresh air which is heated by Contact with the drums 46-47 discharges, into the heat chamber 40 along fthe side of the house. The fresh air may then rise at the rear end of the heat chamber to freely mix with the air circulating therein and through the apparatus.

It is an important function of the presentsystem to re-circulate aportion of the air through the entire house so as to maintain a predetermined degree of moisture or humidity in the air as has been found desirable to prevent too rapid and undue drying of the material adjacent the discharge end of the drying room and also to prevent the hardening of the exterior portion of the substance as it `is initially introduced into the drying chamber. To that end, means are provided for subtracting a portion of the air from the intake end of the drying room and` discharging the same to the atmosphere-exterior to the house, a certain portion of the moist air being by said means restored to the space within the house to be re-used and re-circulated and, also, to be reheated.V

-A means for accomplishing this function is illustrated as comprising a suction blower 55 including a fan or wheel arranged in a housing 56 disposed in a vertical position with an opening in one end wall so that air can be drawn inwardly `at its side remote from the adjacent tier 5. To form the extension of the heat chamber 40 and separate the same from the drying room in which the tiers are arranged, a partition 54 extends from the ,first radiator toward the end 34 and the blower.V casing 56 is .mounted in the partition, thefront end of which partition may be' provided with a passageway 54 to permit a. portion of the air from the drying room to pass around 4the end of the partition 54 toward the outer side of the partition 54, such air being drawn into the blower 55 when it is operated. The blower'casing 56 is provided with a lower tangential discharge branch 57 which is divided` and forms an exhust or discharge flue 58 leading substantially vertically upward and discharging to the atmosphere through the house structure 2, while the'discharge branch 57 is also prol-y vided with an extended connection or iiue 59 that may projectobliquely upwardly4 of the heated and moist air coming from` the drying room and drawn into the blower casing 56 so that the selected portion can be re-used and also for determining 'the quantity to be discharged 0r exhausted .through the outlet flue 58, the end of the discharge pipe 57 of the blower isl provided with a suitable regulator or valve 62 at 'the intersect-ion of the outlet flue 58 'and the flue59, which latter leadsthe selected portion of moist .air through the conduit 60 and the leg 61 into the fresh air tunnel 30 where it is passed about the farther heat drum 46 where it is re-heated and thence passes through the openings 51 and 52 of the tunnel wall into the heat chamber 40. The volume of low'in the iue 58 is controlled by a damper 58 and by valve 62. From this, it will be seen that instead of fresh dry air only being taken as a new Supply through the warming tunnel, there is added to the fresh air taken in through the mouth 30u of thc tunnel a predetermined proportion of previously used moist air, thus not only conserving the heat produced by the furnacesand transmitted by the radiators to the circulated air, but also obtaining and maintaining the desired degree of humidity and also securing fresh air in replacement of the exhausted air passing through the outlet flue 58.

It will be seen that the fresh air passing into the mouth of the tunnel will'be preor initially heated by its contact with the heat tunnel into the heat chamber 40'to be further less of the air tends 5o l heated by the radiator.

vancement of the warm air continues untill heated by passing it to and fro about vthe radiator tubes 39. Again, as above stated, that portion of the heated moist air drawn from the drying room by the blower 55, and which is passed through the return conduit 59, 60, 61, is also reheated while still in its moist condition.

'Power to drive the various circulating fans and blower may be derived from any suitable source, not shown, and transmitted to the shaft ofthe blower from the overhead transverse main shaft 13a on which is provided the master pulley 22. This transmits power, through the pulleys 20--21, to the loose and tight pulleys 17, 18 and 19 by which the direction of drive of the several fan shafts-13 is determined by the attendant to secure the rotation in alternate directions ofthe fans 12 at predetermined and desired intervals and for suitable periods.

The general course of the'. current of air passing through the apparatus is characteristically helical, this being secured by reason o f the provision of the transverse panels and partition formin means which divide the longitudinal drylng roominto a series of sub-chambers on each side of the several overhead partitions 11 with which are coordinating side doors 23 and 43; there being in each of the sub-chambersor spaces a cirf culating fan or propeller 12. y In the rotation of the fans in one direction air is drawn upwardly from the heat chamber and thence -transversely across through the spaces 8 above the ceiling 7 and driven-down between the adjustable doorsor partitions 23 which serve to direct the current of air inwardly toward the drying room where the air passes substantially horizontally through the spaces formed between superposed layers of the material to bedried and which is contained in trays or racks and from which the air passes toward the radiator tubes 39 by which it is heated. By angulanly adjusting the several doors or partitions 23 more or to move longitudinally toward the inlet end of the drying house diverted from one of the transverse spaces 8 toward the next through which it is driven across the drying room beneath the ceiling 7 to the opposite side where it is again .re- This gradual adit passes about the first tier of trays and is drawn by theblower into the discharge and returning flues. T he free, longitudinal progression of the current of air is prevented by the shutters 25 which serve to deflect the a1r transversely vtoward the contiguous tier.

of trays. When the shutters are set against the sides of the tiers, a small portion of the 1 air may creep or escapethrough the spaces formed Ybetween the edges of the shutters andthe adjacent tiers. .It is found in practice that in a given installation or system sufficient heat can be secured from a row of four y radiators disposed in proximity to a row-of four tiers inI advance ofwhich there may be a plurality of tiers adjacent which no radiato-rs are pro-vided. A

What 1s claimed is:

1. An apparatus for drying substance,

comprising a drying room in which the substance may be arranged, means for circulating air through the room, means for discharging a portion of the circulated air, means for replacing the discharged airby fresh air .and including a fresh air conduit, heating drums in the conduit, and means for heating the air before it reaches the substance and after leaving the conduit.

2. An. apparatus ,for drying substance, comprislng a dryingchamber in which the substance may be arranged, a plurality of compartments opening into said chamber, air

Iheating means in said compartments, a conduit through which fresh airis conveyed to the compartments, heating means in said conduit and means for circulatingy the heated air through the chamber and compartments and for returning -a portion of it to the compartments through said conduit.

-3. An apparatus for drying substance, comprising a drying room in which' the substance may be arranged, heating means including pre-heating gas drums and fines and secondary elements, means for conveying fresh air to the heating means so that the air may be heated in stages by said drums and fiues, and means for circulating the heated air through Athe room and returning a part of it to the heating means by way of the fresh air conveying means.

4. An apparatus for drying substance,

comprising a drying room in which the substance may be arranged, heating means in' cluding horizontal drums, means for conveying fresh air tothe heating drums so that the air maybe heated, and means having branches for circulating the heated air duit enclosing a partof the heatingmeans" and for conveyingv fresh air lto the heating means so that the alr y be heated, and means for circulating the cated throu h the room and returning a art of it to t e conduit, the air being initi ly heated in the conveying means, andA reheated after discharge therefrom. f

6. An apparatus for drying 'subdianoa 4substance may be arranged, heating means,

3a conduit for conveying fresh air to the heating means, and means includingvalved iiues for circulating the heated air through Y the room and'returning a part of it to the heating means by way of the fresh Yair conveying conduit so that a mixture of fresh heated air andv of moist .re-heated air is passed over the substance. ,Y

8. An apparatus' for drying substance, comprising a drying chamber, aY radiator arranged adjacent one side Ycf saidchamber,

a fan for circulating air through said radiator and chamber, a furnace, a conduit 'for the gases ofrcombustion connecting said furnace and radiator,- and walls forming a chamber'ir whichthe' conduit is disposed, said -latter chamber being provided with ports openin to the atmosphere and to said rying cham er.: i

VY9. An apparatus for drying substance, comprising a chamber divided into two compartments by a horizontal wall, said compartments being connected ,together at theirI forming a chamber in which the conduitis ends, a fan arranged in the upper compartment to circulate air through, the chamber, Y

a radiator arranged in the lower compartment throughwhich the air passes, .a conduit for gases of combustion arranged below and connected to the radiator, and walls disposed, said latter chamber being revided vwith ports opening to theatlios'p ere and to said first chamber.

10;'An apparatus for drying substance, comprising a drying chamber,t1ers of trays l in said chamber for the substance to bedried arranged with a passage above the material on eachgtray extending through the Ytiers transversely only of said chamber, fans for blowing Ya mass of heated air transversely across said chamber and through said passages, a: blower arranged at the end of the chamber for causing a gradual progression cf said mass of air longitudinally throu h said chamber and means for varying t e amount of air entering said blower. Y

11. Anapparatus forl drying substance,

si comprisin a drying chamber, tiersrof traysl in said c amber for the substance to be dried arranged with a passage above the material on each tray extendingl through the tiers transversely only of said chamber,

fansgfor blowing a mass of heated air transversely 'across said chamber and through said passages, a blower arranged Vat the end of the chamber for causing a gradual progression of said mass ofrair longitudinally through said chamber and onduits connected to the blower for discharging a por tion of said air into the atmosphereand the residue into the opposite end of the chamber. e

Y12. An apparatus for drying-substance, comprising a drying chamber, tlers of trays in said chamber for thesubstance to be dried arranged with a passage above the material n oneach tray extending through the tiers transversely only of said chamber, fans for blowing a mass of heated air transversely across said chamber and through said passages, a blower arrangedl at the end of the chamber for causing a gradual progression of said mass of air longitudinally throu h said chamber and conduits connectedto t e blower for discharging a ortion of said air into the atmosphereV an the residue Ainto the onpositeend of the chamber, and means 'for heating said returnedY air before it enters said chamber.

In testimony whereof, we have hereunto set our hands.

CLAUDE Rans. CHARLES F. EINE. 

